Two sonic booms startled Seattle-area residents Aug. 17 when jet fighters rushed to intercept an airplane that had violated the presidential TFR—a dramatic reminder of the importance of checking notams.

While President Barack Obama was in Seattle, the North American Aerospace Defense Command (NORAD) scrambled two F-15s from the Oregon National Guard in response to a violation of the TFR at about 1:38 p.m. Pacific time, the agency said in a news release. The fighters did not intercept the aircraft before it departed the restricted airspace, but they reached supersonic speeds in flight. Calls to 911 related to the resulting sonic booms overloaded the system, shutting it down temporarily, according to local news reports.

“This incident demonstrates how a careless mistake can have far-reaching consequences,” said AOPA Vice President of Operations and International Affairs Craig Spence. “When one pilot makes the news for violating a TFR, it can set back progress we’ve made on improving access for the hundreds of thousands who haven’t.”

AOPA has been working with the Transportation Security Administration, the Secret Service, and the FAA to mitigate the impact of presidential TFRs on general aviation, and recently an increase in the use of gateway airports and screening procedures have allowed pilots to access facilities located within the inner 10-nautical-mile-radius area known as the “ GA no-fly zone.” But violations may hinder efforts to improve access further.

Obama was in Seattle for a campaign fundraising event for Sen. Patty Murray, and the president’s busy travel schedule this week means pilots across the country should be especially vigilant in checking notams. Obama’s travel schedule over the course of the week included Panama City, Fla.; Milwaukee, Wis.; Los Angeles; Seattle; Columbus, Ohio; Miami, Fla.; and Martha’s Vineyard, Mass. Spence warned that the president may be traveling frequently for campaign events during election season.